How accurate are urine pregnancy tests, in the afternoon, a week after an expected period?

Negative UCG: Urinary pregnancy tests are becoming increasingly sensitive; a positive test can occur just a few days after the expected period. Since urine is more concentrated early in the morning, this is the best time to test. Although a positive test is very reliable, a negative test can occur simply from ovulation occuring later in the cycle than expected. No test can confirm conception from last night!